To provide a contouring device for rotating a cutting tool having a cutting blade and revolving the cutting tool around a work which is free from any play in the revolving radius, capable of performing smooth drive, and realizing the contouring device by a simple configuration, and reducing the number of parts.

The contouring device comprises an intermediate member 62 which is interposed between a revolving shaft 8 and an eccentric shaft 10 and movable in the axial direction, and a means to move the intermediate member 62 in the axial direction. The intermediate member 62 is connected to the revolving shaft 8 via a ball coupling consisting of a ball 67 which is integrally revolved with the revolving shaft and engaged with multi-screw grooves of the eccentric shaft 10. In a radius changing mechanism of a contouring machine, the ball 67 is arranged on and held by a tip of a holder 81 to be mounted from the outer side of the intermediate member 62.